Animals can be unpredictable, and should be safely restrained while being transported. Unrestrained animals are the cause of many accidents, as they can distract or interfere with the driver's ability to control or operate the vehicle. Moreover, unrestrained animals can become large projectiles in an accident, exerting hundreds or even thousands of pounds of impact force, injuring not only themselves but others in the vehicle. Unrestrained animals can even be ejected.
Moreover, restraining an animal will also help stabilize the animal when a vehicle is braking, cornering, or accelerating. This in turn will also help to calm an animal that is fearful in a moving vehicle, or one that suffers from carsickness. An unrestrained animal, such as a dog, in an accident is likely in shock, confused, or injured. In this condition, the animal is likely to be protective, and unrestrained may attack rescuers.
Unrestrained animals are also problematic when the windows of a vehicle are opened. An animal, such as a dog, should not be allowed to put its head outside the vehicle because the animal can be injured by particles of debris or become ill from having cold air forced into its lungs. The animal that is allowed to have its head outside of a vehicle can be subjected to, for example, inner ear damage, lung infections and possible eye damage. Moreover, unrestrained animals can jump out of cars. Even in a slow moving vehicle, an animal that jumps out of an open window can suffer serious injury or even death.